<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
    <title>监听</title>
</head>
<body>

<script src="https://unpkg.com/vue"></script>
<!-- 因为 AJAX 库和通用工具的生态已经相当丰富，Vue 核心代码没有重复 -->
<!-- 提供这些功能以保持精简。这也可以让你自由选择自己更熟悉的工具。 -->
<script src="https://cdn.jsdelivr.net/npm/axios@0.12.0/dist/axios.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/lodash@4.13.1/lodash.min.js"></script>

<div id="app_1">

    <p>
        ask question:
        <input v-model="question">
    </p>
    <p>answer:{{answer}}</p>

</div>

<script>

    let app_1 = new Vue({
        el: "#app_1",
        data: {
            question: "",
            answer: "I cannot give you an answer until you ask a question!"
        },
        watch: {
            question: function () {
                this.answer = "searching.....";
                this.getAnswer();//调用接口，获取answer
            }
        },
        methods: {

            // `_.debounce` 是一个通过 Lodash 限制操作频率的函数。
            // 在这个例子中，我们希望限制访问 yesno.wtf/api 的频率
            // AJAX 请求直到用户输入完毕才会发出。想要了解更多关于
            // `_.debounce` 函数 (及其近亲 `_.throttle`) 的知识，
            // 请参考：https://lodash.com/docs#debounce
            getAnswer: _.debounce(
                function () {

                    if (!this.question) {
                        this.answer = "I cannot give you an answer until you ask a question!";
                        return;
                    }

                    //如果问题中没有 ?
                    if (this.question.indexOf("?") === -1) {
                        this.answer = "question usually contain a question mark :-)";
                        return;
                    }

                    this.answer = 'Thinking...';

                    var vm = this;
                    axios.get('https://yesno.wtf/api')
                        .then(function (response) {
                            debugger
                            vm.answer = _.capitalize(response.data.answer)
                        })
                        .catch(function (error) {
                            debugger;
                            vm.answer = 'Error! Could not reach the API. ' + error
                        })

                },
                500
            )

        }
    })

</script>

</body>
</html>